It's a very consistent outcome: the elements on the map aren't rendered until the player (pardon me, observer) enters the map, at which point things become either particles or waves as needed...
Trying to get my head round quantum computers
- Thread starter rubberduck
- Start date
It's a very consistent outcome: the elements on the map aren't rendered until the player (pardon me, observer) enters the map, at which point things become either particles or waves as needed...
Soldato
- Joined
- 16 May 2007
- Posts
- 3,221
So a zx81 including the 16k RAM pack is a quantum computer ?
It is a scientific fact.
Most people miss the original intention of that scenario anyhow. Its a bit more revealing if you look at it from the perspective of the atomic trigger, etc. even when talking about the cat being both alive and dead people are often still conceptualising it in the back of their mind in terms of classical physics.
Associate
- Joined
- 10 Apr 2008
- Posts
- 1,010
I thought the cat in the box example was also supposed to have some radioactive isotope in the box too, and at the point it decays it would trigger a device to kill the cat. The cats state merely shows if the decay has happened or not yet. You don't know the state of the radio active material, so you don't know the state of the cat, until you open the box.
Soldato
- Joined
- 14 Jul 2005
- Posts
- 9,383
- Location
- Birmingham
no its not its a theory.
Soldato
- Joined
- 14 Jul 2005
- Posts
- 9,383
- Location
- Birmingham
Ive been reading up about the double slit experiment, the information about it seems to be very weak, such that it may never have been conducted at all in practice - at least not quite in the way its portrayed.
The first part of the experiment is totally legit. You send a beam of light, or an electron through the slits, and you get the classic interference pattern at the detector plate. Fine.
However the second part of the experiment is very weak indeed. In practice, one cannot detect an electron without interfering with it. The image of a detector somehow pointed at the slit to detect the passage of an electron is not possible in practice. The only way to detect an electron is to have some physical interaction with it. So we aren't simply observing the electron's state, we are interferring with it's state. Is it any wonder that this physical interaction destroys the interference pattern?
The first part of the experiment is totally legit. You send a beam of light, or an electron through the slits, and you get the classic interference pattern at the detector plate. Fine.
However the second part of the experiment is very weak indeed. In practice, one cannot detect an electron without interfering with it. The image of a detector somehow pointed at the slit to detect the passage of an electron is not possible in practice. The only way to detect an electron is to have some physical interaction with it. So we aren't simply observing the electron's state, we are interferring with it's state. Is it any wonder that this physical interaction destroys the interference pattern?
Soldato
- Joined
- 15 Feb 2012
- Posts
- 3,308
- Location
- 2
This is the essence of the Schrodinger's Cat thought experiment in a nutshell. The cat is the electron being measured and opening the box is the process of measuring it. It isn't that we change the cat in a human-perceptible way, e.g. from alive to dead or vice versa, because cat 'aliveness' (vitality?) isn't a bona fide quantum state. The slit experiment simply exaggerates the effect to make it obvious.
To abstract a little, quantum mechanics simply attempts to describe the interactions between matter, energy, position, and time. The manner in which one measures/observes a quantum state necessarily changes it. I quite like the idea that, if we didn't have eyes we would be sensing by sound. In this case, the speed of sound would define time and distance, despite there being a faster value (which would be unknown/unobservable to us). It probably isn't a good example because the speed of sound isn't constant, but it's the link between senses and measurement that is important.
The interesting applications are comms and computing. This arises from coupled quantum states (entanglement), where two, or more, states depend on each other. For comms, these states appear to depend on their entangled 'other' despite distance and time. This where you go with Einstein and Rosen and their 'hidden variables' explanation... Einstein didn't want to believe there might be a value faster than the speed of light because his theories depended on it, or Bell and his super-determinism.
It is interesting that qubits rely on imaginary numbers, which implies the addition of an extra orthogonal dimension (such as the imaginary plane). This is, of course, required to explain periodic behaviour in the original dimension (e.g. a rotating phasor). Furthermore, the combination of a probability density function (say, a Gaussian) and a wave function (a sinusoid will do) gives rise to a Morlet wavelet that can be used to investigate both the time and frequency components of a physical signal. In some sense, time and frequency are entangled.
It's a fascinating bit of the pie of science, and very near the centre, so it touches many other scientific disciplines. And philosophy.
Wgat you have to understand is the universe is generated it on the fly from these probabilistic wave functions. It doesn't store the history of the balls, it just has these fuzzy wave functions which can generate outcomes when they become entangled with systems. The history is generated. https://en.m.wikipedia.org/wiki/Delayed_choice_quantum_eraser
When you zoom out to the macro scale the fuzzy probabilities add up in a way that looks "real" in classical physics. It's a resource saving mechanism. The resources required to store a function is hugely less than required to store coordinates/history/information about system states. It strongly suggests the whole thing is a computer.
When you zoom out to the macro scale the fuzzy probabilities add up in a way that looks "real" in classical physics. It's a resource saving mechanism. The resources required to store a function is hugely less than required to store coordinates/history/information about system states. It strongly suggests the whole thing is a computer.
Soldato
- Joined
- 14 Nov 2002
- Posts
- 7,773
- Location
- Under the Hill
Yes, that is the premise of the experiment. I think Dan missed this lightbulb moment and ended up having to switch degrees to something easier
.I remember reading about a hypothetical experiment that may eventually become possible to perform involving a variant of the double slit experiment using gravitational lensing on photons that have traveled from a "Distant" Galaxy.
The issue is how something that is done "Now" affects something else that happened billions of years ago..
Quantum mechanics is mad
It sure is
The issue is how something that is done "Now" affects something else that happened billions of years ago..
The inference I think would be that anything that hasn't been directly observed would exist only in a 4D like state that is for a want of a better way to put it a loose description that covers the range of possibilities without determining any one - when you add in the key (time/observer) it results in a coherent 3D outcome. Though there are a lot of complexities to that and potential pitfalls.
I have always liked the David Deutch/Crighton-Timeline interpretation of the double slit experiment.
It also covers Quantum Computers if I recall correctly. QC's power comes from the way they are effectively massively parallel machines sharing the computation with other machines in other parallel universes.
(I always did like Sliders, I got a box set from the Cex shop a while back, I will have a bingeout one day
)
Soldato
- Joined
- 21 Oct 2011
- Posts
- 22,500
- Location
- ST4
"Anyone who is not shocked by quantum theory has not understood it."
Its not hard the is 2 normal states in computing 0,1 in quantum computing there is 3. 0,1 and the tricky bit is 01, so the bit is neither on or off so gives you another computational figure on the binary scale.
Its called a Qbit its neither 1 or 0. Its a strange configuration in maths but it can work.
Its called a Qbit its neither 1 or 0. Its a strange configuration in maths but it can work.
Last edited:
Problem is trying to understand a Qubit in that manner is completely misleading and people still think in terms of classical computing.
Soldato
- Joined
- 15 Feb 2012
- Posts
- 3,308
- Location
- 2
It is to be expected, since an uninitialised bit is in an unknown state, just a different unknown (either instead of both).
Soldato
- Joined
- 16 Aug 2009
- Posts
- 8,197
The issue is how something that is done "Now" affects something else that happened billions of years ago..
Quantum entanglement presumably. Two particles that are entangled can influence each other even when on opposite sides of the universe. Which gives the possibility of faster than light communication, in theory.